- Method
glTexSubImage2D
void glTexSubImage2D(int target, int level, int xoffset, int yoffset, object|mapping(string:object) width, object|mapping(string:object) height, object|mapping(string:object) format, object|mapping(string:object) type, array(object|mapping(string:object)) pixels)
- Description
Texturing maps a portion of a specified texture image
onto each graphical primitive for which texturing is enabled.
To enable and disable two-dimensional texturing, call glEnable
and glDisable with argument GL_TEXTURE_2D .
glTexSubImage2D redefines a contiguous subregion of an existing two-dimensional
texture image.
The texels referenced by pixels replace the portion of the
existing texture array with x indices xoffset and "xoffset"~+~"width"~-~1,
inclusive,
and y indices yoffset and "yoffset"~+~"height"~-~1, inclusive.
This region may not include any texels outside the range of the
texture array as it was originally specified.
It is not an error to specify a subtexture with zero width or height, but
such a specification has no effect.
- Parameter target
Specifies the target texture.
Must be GL_TEXTURE_2D .
- Parameter level
Specifies the level-of-detail number.
Level 0 is the base image level.
Level n is the nth mipmap reduction image.
- Parameter xoffset
Specifies a texel offset in the x direction within the texture array.
- Parameter yoffset
Specifies a texel offset in the y direction within the texture array.
- Parameter width
Specifies the width of the texture subimage.
- Parameter height
Specifies the height of the texture subimage.
- Parameter format
Specifies the format of the pixel data.
The following symbolic values are accepted:
GL_COLOR_INDEX ,
GL_RED ,
GL_GREEN ,
GL_BLUE ,
GL_ALPHA ,
GL_RGB ,
GL_RGBA ,
GL_LUMINANCE , and
GL_LUMINANCE_ALPHA .
- Parameter type
Specifies the data type of the pixel data.
The following symbolic values are accepted:
GL_UNSIGNED_BYTE ,
GL_BYTE ,
GL_BITMAP ,
GL_UNSIGNED_SHORT ,
GL_SHORT ,
GL_UNSIGNED_INT ,
GL_INT , and
GL_FLOAT .
- Parameter pixels
Specifies a pointer to the image data in memory.
- Throws
GL_INVALID_ENUM is generated if target is not GL_TEXTURE_2D .
GL_INVALID_OPERATION is generated if the texture array has not
been defined by a previous glTexImage2D operation.
GL_INVALID_VALUE is generated if level is less than 0.
.P
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GL_INVALID_VALUE may be generated if level is greater
than log sub 2max,
where max is the returned value of GL_MAX_TEXTURE_SIZE .
GL_INVALID_VALUE is generated if "xoffset" ~<~ ~-b,
("xoffset"~+~"width") ~>~ (w~-~b),
"yoffset" ~<~ ~-b, or ("yoffset" ~+~ "height") ~>~ (h~-~b).
Where w is the GL_TEXTURE_WIDTH ,
h is the GL_TEXTURE_HEIGHT , and b is the border width
of the texture image being modified.
Note that w and h include twice the border width.
GL_INVALID_VALUE is generated if width or height is less than 0.
GL_INVALID_ENUM is generated if format is not an accepted
format constant.
GL_INVALID_ENUM is generated if type is not a type constant.
GL_INVALID_ENUM is generated if type is GL_BITMAP and
format is not GL_COLOR_INDEX .
GL_INVALID_OPERATION is generated if glTexSubImage2D is executed
between the execution of glBegin and the corresponding
execution of glEnd .
GL.glTexParameter()